According to the IIA's guidance on independence and objectivity, an internal auditor who has been transferred from another department should not audit any function or process of their former department until a reasonable period has passed, typically around one year. Participating in such projects or audits could impair their objectivity because of familiarity or bias related to their former role and relationships within the department. In this case, providing an opinion on a project related to their former department could impair objectivity due to potential conflicts of interest.References: The Institute of Internal Auditors (IIA) - Standards for Objectivity